Sylpheed is a simple, lightweight but featureful, and easy-to-use e-mail client (mailer, MUA). Sylpheed runs on Unix-like systems such as Linux, BSD, and Mac OS X. It also supports Windows. Sylpheed uses GTK+ GUI toolkit. The newest version of Sylpheed works with GTK+ 2.4 or later (2.6 or later is recommended). Sylpheed is a free software distributed under the GNU GPL (the library part is GNU LGPL). You can freely use, modify and redistribute it under the license.
Sylpheed has the following features:
* Simple, beautiful, and well-polished user interface
* Comfortable operationality which is built in detail
* Well-organized, easy-to-understand configuration
* Lightweight operation
* High reliability
* Internationalization and Multilingualization support
* High-level Japanese processing
* Various protocols support
* Security features (GnuPG, SSL/TLSv1)
* Powerful filtering and search
* Junk mail control
* Flexible cooperation with external commands
* In the address book, the import of CSV and Tab-separated text file was implemented.
* 'Within 1 day' and 'Recent 5 days' was added to the quick search rule.
* The toolbar style switch was added to the toolbar context menu.
* Stop button now cancels all sessions.
* The limitation of the nesting level of MIME structure was relaxed.
* A margin for text was added to the composition window.
* An error dialog is displayed if the execution of junk filter command fails.
* The overwrite confirmation of the file selection dialog was improved.
* ISO-8859-16 was supported in code conversion.
* Several UI problems in the address book were fixed.
* The stability of the cancellation of POP3/SMTP session was improved.
* The bug that the displayed number of message becoming incorrect on folder search was fixed.